Such injection valves are in particular used for metering fluid for a combustion process into a combustion chamber of a cylinder of an internal combustion engine.
The increasingly strict statutory regulations on permissible pollutant emissions of motor vehicles in which internal combustion engines are mounted require that the pollutant emissions be kept as low as possible in the operation of the internal combustion engine. This can be done on the one hand by reducing the pollutant emissions which form during the combustion of the air/fuel mixture in the specific cylinder of the internal combustion engine. On the other hand, exhaust gas after treatment systems are being used in internal combustion engines, that convert the pollutants formed during the combustion process of the air/fuel mixture in the respective cylinders into harmless substances. For this purpose, exhaust gas catalytic converters are used, which convert carbon monoxide, hydrocarbons and nitrogen oxides into harmless substances. Both the explicit influencing of the generation of pollutant emissions during combustion and the conversion of pollutant components with a high level of efficiency by using an exhaust gas catalytic converter require a very accurately adjusted air/fuel ratio in the cylinder in question.
In this context, it is desirable for the fuel metering through the corresponding injection valve to be as accurate as possible.
A method for controlling an electromagnetically operated switching valve is known from DE 102 35 196 A1. In order to operate a valve, a coil current is applied to an electromagnet, it being possible that the application of the coil current has a rising and a falling switching edge. The method involves superimposing a braking pulse on the coil current at a time interval from the switching edge of the valve actuating coil current to retard the movement of the valve body. The current in the coil of the electromagnet is measured with a current sensor and fed to an observer unit, which determines a path covered by the valve body. The path determined is fed to an impact energy observer. The observer determines as a function of the switching valve path, the impact energy generated from it during impact.